Circuit breaker



H. G. SMITH, JR ZWSEEI CIRCUIT BREAKER March 31, 1936.

Filed Nov. '7, 1934 INVENTOR Harry 6 sm/r/z J77 ATTORNEY Patented Mar.31, 1936 UNITED STATES PATENT OFFICE CIRCUIT BREAKER Harry G. Smith,Jr., Union,

Edison-Splitdorf Corporation,

N. J., assignor to West Orange,

6 Claims.

This invention relates to circuit breakers particularly of the type usedin connection with ignition systems for internal combustion engines, andmay be used in connection with a magneto or battery system.

In either system of ignition, it is highly essential that the contactpoints of the circuit breaker make contact over the entire surfaceswhich are in engagement when the breaker is closed. In ignition circuitbreakers, the movable element carries a bumper which is adapted toengage or be engaged by a cam member to open the contacts at the propertime. Due to the wear of the bumper and the cam or cams, and the contactpoints themselves, it becomes necessary after a time to adjust thecontacts so that the breaker opens only a certain amount in order toobtain the best results.

In many types of ignition circuit breakers the stationary contact pointis usually carried on an adjustable screw and when the screw is turnedto make the adjustment previously referred to, the parallelism betweenthe contact faces of the points is lost, and to bring these faces backinto parallelism, the contacts have to be filed or sandpapered orotherwise operated on to bring back the parallelism of the contactfaces. This is objectionable for the reason that in many types ofcircuit breakers very valuable material such as platinum and iridium isused, and a less expensive metal such as tungsten. Yet in each case thismaterial is wasted and considerable time is lost in making adjustment,which while .5. it looks simple, is not readily carried out. 3

In Ratcliff Patent 1,305,165, issued May 27, 1919, there is shown anddescribed a circuit breaker which overcomes, by a patent construction,the difficulties previously described. In the Ratcliff construction,however, a separate piece for carrying the stationary contact isrequired and it is mounted around the same axial center as the circuitbreaker arm, so that its adjustable movement together with the movementof the circuit breaker arm, and consequently the points carried by theseparts, are along the arc of the same circle.

I have found, however, that a much simpler breaker can be made withoutthese points being movable on the same are to accomplish the samepurpose; or, stated in another way, I have accomplished the main objectof maintaining the parallelism of the contact faces while adjusting thedistance of opening of the contacts, in a different manner thandisclosed in the Ratcliff patent.

My invention will be readily understood by reference to the annexeddrawing, wherein:

Figure 1 is a plan view of my improved type of circuit breaker includedin a suitable support or breaker housing, together with a cam for 5operating the movable part of the breaker.

Figure 2 is a section on the line 2-2 of Figure 1. Figure 3 is a view onthe line 33 of Figure 1. Figure 4 is a view similar to Figure 1, butshowing a modified form of means for mounting and 0 adjusting one of thecircuit breaker members.

Figure 5 is a separate view of the breaker mechanism shown in Figure 4,but showing in dotted lines an adjusted position of the parts.

In the different views, I is a mounting mem- 15 her which may begenerally referred to as a breaker housing having a lever 2 for shiftingthe mounting member to advance or retard position. Pivoted in anysatisfactory manner as by a pivot screw 3, is a breaker member 4, thefree 20 end of which has an outwardly projecting end or lug 5 to whichis securely anchored a contact point 6 which may be of any suitablematerial satisfactory for use with the apparatus to which it is related.26 The breaker member 4 has securely anchored thereto a pivot pin orstud l on which is mounted a movable breaker arm 8 carrying on its freeend a contact 9 that is adapted to cooperate with the contact 6. Thebreaker arm 8 is insulated 0 from the piece or stud l as by a suitableinsulator l8 so that current may be conducted to the breaker arm 8through the spring H, which may have an extra current-carrying memberassociated therewith, both of which are connected to 5 a terminal studl2 fastened to the mounting member I but insulated therefrom. The arm 8carries the usual bumper l3 and is adapted to be engaged by cam I 4carried on an operating shaft connected with the mechanism. The cam 40I4 is preferably made of some self-lubricating material such asaggregates formed of finely divided metal and subsequently soaked inlubricant. The contacts 6 and 9 are normally held in closed position bythe spring I l. 4

The breaker member 4 is provided with an oblong opening I5 to receive alocking screw l6 which is used to hold the member 4 in adjustedposition. The breaker member 4 is also provided with a second elongatedhole ll within which is positioned an adjusting screw having aneccentric head IE, so that as the head I8 is turned, it engages the sideWalls of the hole I! to move the breaker member 4 about its pivotalscrew 3.

It will be seen from this construction that since allelism of theircontact faces.

the movable breaker arm 8 is carried on the breaker member 4, when thelatter member is adjusted as above described, no change in the positionof the contacts 6 and 9 takes place as the breaker arm 8 is movedsimultaneously with the member 4, and consequently the contact points 6and 9 maintain the same relative par- The reason for adjusting thebreaker member 4 is, of course, so that the distance of the openingsbetween the points 6 and 9 may be set to the desired distance. In otherwords, it is common practice to adjust the ignition circuit breaker sothat the contacts open approximately twenty thousandths of an inch. Thisadjustment may vary somewhat from this figure in accordance with thetype of apparatus with which the breaker is used. Furthermore,adjustment is needed to take up or compensatefor wear on the contactpoints and on the bumper I3 In the form of device shown in Figures 4 and5, the breaker member 4, instead of being pivoted. in the manner shownin Figure l, is provided with an additional oblong hole [9 similar toI5, so that after the set screws l6 are loosened, the member 4 may beadjusted laterally and then the screws l5 tightened up, looking themember 4 in its newly adjusted position; but as before, the breaker arm8 maintains its same relative position and no change in the parallelismof the faces of the contact points 6 and 9 takes place. This is clearlyindicated by the tWo positions of the circuit breaker parts shown inFigure 5.

From what has been said,.it will be seen that the breaker member 4 andmovable contact arm 8 constitute a unit assembly which can be puttogether entirely separate from the mounting member or house, or abreaker face plate some-- times used for carrying these par-ts. Thearrangement thus provides a construction which will enable the fixedcontact 6 carried on the lug 5 to be adjusted by slightly bending thelug 5 so as to bring the faces of the contact points into substantiallyperfect parallelism before any part of this assembly is put into theapparatus with which it is to be used, whereby, after it is assembled inthe said apparatus, only the adjustment of the member 4 with respect tothe cam is required. 7

What I claim is:

1. In a device of the character described, the combination of twocooperating members, one pivotally mounted on the other, and eachcarrying a contact for conjoint action one on the other, means formoving said pivotally mounted member to open and close said contacts,said one member, carrying the other pivoted thereto, being adjustableprimarily for varying the amount of separation of the contacts.

2. In a device of the character described, the combination of a mountingmember, a circuit breaker member carrying a contact and being adjustablymounted on said mounting member, an arm pivotally mounted on saidbreaker member and having a contact cooperating with saidfirst-mentioned contact, the adjustable mounting of said circuit breakermember being primarily for varying the amount of separation of thecontacts.

3. In a device of the character described, the combination of a mountingmember, a circuit breaker member carrying a contact and being adjustablymounted on said mounting member, a post carried on said breaker member,an arm pivotally mounted on the post, said arm having a contact forcooperation with said firstmentioned contact, the adjustable mounting ofsaid circuit breaker member being primarily for varying the amount ofseparation of the contacts.

4. In a device of the character described, the combination of a mountingmember, a circuit breaker member carrying a contact and being shiftablymounted on said mounting member, a movable member carried on saidbreaker member and having a contact cooperating with saidfirst-mentioned contact, the shiftable mounting of said circuit breakermember being primarily for varying the amount of separation of thecontacts.

5. In a circuit breaker having cooperative contacts, means for openingand closing said contacts, means for retaining the contacts in para]-lelism while varying the amount of opening of the contacts'whichcomprises a shiftable member carrying one of the contacts and a membermovably carried on said shiftable member and carrying the other contact,said breaker member being adjustable primarily for varying the amount ofseparation of the contacts.

6. In a device of the character described, the combination of amountingmember, a circuit breaker member having a relatively stiff yetadjustable lug carrying a contact, said breaker member being adjustablymounted on said mounting member, a movable member carried on saidbreaker member and having a contact cooperating with the contact on saidlug, said breaker member being adjustably mounted primarily for varyingthe amount of separation of the contacts.

' HARRY G. SMITH, JR.

